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Nutrient Management (nutrient + management)
Selected AbstractsNutrient management on farms, or ,You get out what you put in'JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 2 2007Keith WT Goulding First page of article [source] Mulberry nutrient management for silk production in Hubei Province of ChinaJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 2 2009Fang Chen Abstract The silk industry is important for south China's rural economy. Leaves of mulberry (Morus spp.) are used for silkworm production. Hubei province is one of the main silk-producing provinces in China. The objectives of this research were to survey the fertilization practices in the mulberry-producing regions in the province and to determine the best nutrition-management practice for mulberry plantations. A survey and a series of field experiments with N, P, K, and micronutrients were conducted from 2001 to 2002. In addition, a silkworm-growth experiment was also conducted by feeding leaves harvested from various fertilization treatments. The results indicate that poor soil fertility and unbalanced fertilization were the main factors limiting mulberry-leaf yield and quality in Hubei province. Nitrogen fertilization of mulberry has reached a high level (454,kg ha,1 y,1) in Hubei province, but P- and K-fertilization rates have not been matched with N-fertilization rates as farmers are not aware of the significance of P and K. Balanced fertilization showed positive nutrient interactions with respect to mulberry yield and quality. Potassium application increased yield and quality (protein and sugar concentration) of mulberry leaves. Silkworm growth and cocoon quality were improved when silkworms were fed with the leaves derived from K-fertilized plants in comparison with those taken from control plots. Application of Mg, S, and B also significantly improved leaf sugar, essential and total amino acid concentrations, but did not increase leaf yield significantly. It is concluded that a fertilizer dose of 375,kg N ha,1, 66,kg P ha,1, and 125,kg K ha,1 is suitable for the cultivation of mulberry in the Hubei province along with Mg, S, and B, wherever necessary, for the improvement of yield and quality of mulberry leaves. [source] Effects of nitrogen supply on water-use efficiency of higher plantsJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 2 2008Holger Brueck Abstract The worldwide increase of food demand and reduced sweet-water availability in some important food-producing regions raised interest in more efficient water use, which has become one of the central research topics in agriculture. Improved irrigation management and reduced bare-soil evaporation have highest priority to increase agronomic water-use efficiency (WUE). Compared to these technical (irrigation) and basic (crop production) management options, effects of nutrient management on WUE were less frequently considered. Twenty-nine publications on nitrogen (N) effects on biomass WUE of container-grown plants are considered in this review. Most of them indicate positive N effects on WUE, and relevance of N effects on intrinsic WUE and unproductive water and carbon loss is discussed. A plot of 90 published data of percent decreases of WUE and dry mass under variable N supply is presented. Extrapolation of biomass WUE from leaf measurements of intrinsic WUE is critically reviewed. The positive correlation between WUE and dry-mass formation suggests that physiological rather than stomatal effects are more important in order to explain positive N effects on WUE. [source] Farmers' perceptions of soil erosion and its consequences in India's semiarid tropicsLAND DEGRADATION AND DEVELOPMENT, Issue 3 2005J. Kerr Abstract This paper investigates farmers' perceptions of soil erosion and how it affects crop yields, land values, and private conservation investments in India's semiarid tropics. It is based on three types of data: (1) a survey of farmers in three study villages; (2) a plot survey by a professional soil surveyor in the same villages; and (3) experimental and simulated data from nearby research stations with similar conditions. Farmers' perceptions of erosion are compared to the surveyor's using kappa, a statistical measure of interrater agreement. Perceived erosion,yield relationships are estimated econometrically and compared to experimental and simulated data. Effects on land values and conservation investments are estimated econometrically. Findings suggest that farmers are keenly aware of rill erosion but less aware of sheet erosion; kappa values ranging from 0 to 0·28 suggest low agreement with the soil surveyor. They anticipate annual yield losses of 5·8,11,per,cent due to rill erosion; these figures are reasonably consistent with those from nearby research stations. They anticipate yield increases of 3·8,14·5,per,cent due to installation of soil conservation bunds, largely because they can harvest soil from up the slope and capture organic matter. Perceived erosion has some effect on land values and soil conservation investments, but other factors such as irrigation and soil type have a much greater effect. These findings suggest that promoting soil conservation requires capitalizing on farmers' interest in short-term gains, such as from water and nutrient management. Copyright © 2005 John Wiley & Sons, Ltd. [source] Soil carbon sequestration in China through agricultural intensification, and restoration of degraded and desertified ecosystems,LAND DEGRADATION AND DEVELOPMENT, Issue 6 2002R. Lal Abstract The industrial emission of carbon (C) in China in 2000 was about 1,Pg,yr,1, which may surpass that of the United States (1,84,Pg,C) by 2020. China's large land area, similar in size to that of the United States, comprises 124,Mha of cropland, 400,Mha of grazing land and 134,Mha of forestland. Terrestrial C pool of China comprises about 35,60,Pg in the forest and 120,186,Pg in soils. Soil degradation is a major issue affecting 145,Mha by different degradative processes, of which 126,Mha are prone to accelerated soil erosion. Total annual loss by erosion is estimated at 5,5,Pg of soil and 15,9,Tg of soil organic carbon (SOC). Erosion-induced emission of C into the atmosphere may be 32,64,Tg,yr,1. The SOC pool progressively declined from the 1930s to 1980s in soils of northern China and slightly increased in those of southern China because of change in land use. Management practices that lead to depletion of the SOC stock are cultivation of upland soils, negative nutrient balance in cropland, residue removal, and soil degradation by accelerated soil erosion and salinization and the like. Agricultural practices that enhance the SOC stock include conversion of upland to rice paddies, integrated nutrient management based on liberal use of biosolids and compost, crop rotations that return large quantities of biomass, and conservation-effective systems. Adoption of recommended management practices can increase SOC concentration in puddled soil, red soil, loess soils, and salt-affected soils. In addition, soil restoration has a potential to sequester SOC. Total potential of soil C sequestration in China is 105,198,Tg,C,yr,1 of SOC and 7,138,Tg,C,yr,1 for soil inorganic carbon (SIC). The accumulative potential of soil C sequestration of 11,Pg at an average rate of 224,Tg,yr,1 may be realized by 2050. Soil C sequestration potential can offset about 20 per cent of the annual industrial emissions in China. Copyright © 2002 John Wiley & Sons, Ltd. [source] | ||||||||||